feat: initial HarborForge project structure

- Docker Compose with MySQL + FastAPI backend
- Issue model with RESOLUTION type (for agent deadlock resolution)
- Project, User, Comment models
- Basic CRUD API endpoints
- .env.example for configuration

.env.example

@@ -0,0 +1,11 @@
+# HarborForge Environment Variables
+
+# Database
+MYSQL_ROOT_PASSWORD=harborforge_root
+MYSQL_DATABASE=harborforge
+MYSQL_USER=harborforge
+MYSQL_PASSWORD=harborforge_pass
+
+# Application
+SECRET_KEY=change-me-use-openssl-rand-hex-32
+LOG_LEVEL=INFO